1. Field
This disclosure relates to a thin film solar cell, and a method of fabricating the thin film solar cell.
2. Description of the Related Art
For commercialization of thin film solar cells, a method to improve fabrication efficiency of thin film solar cells, and reduce fabrication costs, is desirable. For commercial processes, polycrystalline silicon is preferred. The temperature of a thermal process is restricted by the thermal stability of any substrate materials. If the substrate comprises a material that has low thermal stability, for example, glass or plastic, the substrate cannot be thermally processed at an ultra-high temperature. Consequently, when a substrate of low thermal stability is used, crystallization of silicon is performed at a temperature that the substrate can sustain without substantial degradation, and as a result polycrystalline silicon of satisfactory quality cannot be obtained. In addition, even when a thermal process is performed at a temperature that the substrate can sustain without degradation, the substrate still can be exposed to a locally high temperature, and thus the substrate may be damaged or may deform.
In electronic devices other than thin film solar cells, in which a crystalline material layer obtained from an amorphous material is used as an active layer, the temperature for crystallizing the amorphous material is selected by the thermal process temperature, which is restricted by the thermal stability of the substrate that supports structural materials of the electronic device. Accordingly, limits on process temperatures limit improvements in the quality of a crystalline thin film.